Chlamydia are obligate intracellular parasites that are ubiquitous throughout the animal kingdom and are known to cause a variety of diseases. The Chlamydia genus has two recognized species, C. trachomatis and C. psittaci, with further differentiation of C. trachomatis into three biovars. C. trachomatis, the species that is a primary human pathogen causes ocular, respiratory, and urogenital infections. C. trachomatis can initially colonize the mucous membranes, including the conjunctive, nasopharynx, rectum, urethra, and cervix, after which the infection may spread to affect the deeper organ systems.
The other species of Chlamydia, C. psittaci, is responsible for the human respiratory disease, psittacosis. Psittacosis is usually contracted by exposure to infected birds, outbreaks of psittacosis having occurred in association with turkey and duck processing plants and among pet shop clientele. The disease often resembles atypical pneumonia and may range in severity from mild to fatal. Although epidemics of such pneumonia have usually been traced to injected birds, an avian vector is not always found. For instance, during a radiographic survey in northern Finland in 1978, an epidemic of mild pneumonia was found in two communities; however, avian transmission was not detected.
Seroepidemiological studies have implicated an unusual strain of Chlamydia in this and several other pneumonia epidemics in northern Europe. This new strain of Chlamydia has more recently been established as an important respiratory pathogen, being responsible for perhaps up to 12% of the atypical pneumonia cases in adult populations studied. However, most infections have been inadequately treated with antibiotics due to a mistaken belief that the causative agent was Mycoplasma pneumoniae or influenza virus A or B. While antibiotic treatment with erythromycin in the low doses used for M. pneumoniae is effective against Mycoplasma infection, erythromycin at this dose is not effective against chlamydial infections. Further, these infections are often characterized by a relapsing illness after an apparent resolution of symptoms.
In light of this associated between a new strain of Chlamydia and acute respiratory disease, it would be highly desirable to provide an accurate and cost-effective method for diagnosing the presence of this new strain thereby permitting an effective antibiotic treatment of the primary infection. The present invention provides such a method and is further characterized by other related advantages.